Liquid cooled supercharger



5Pf 4, 1945' H. c. HILL 2,384,251

LIQUID COOLED SUPEHCHARGER FiledA Jan. 14, 1943 2P- am 2-'Il"Illlllllll'llllgfllllll.

Stumm ATTORNEY atente Sept. 4, 45

LIQUID cooLED ,SUPERCHARGER Henry CrHill, Montclair, N. J., assignor toWright Aeronautical Corporation, a corporation of New York ApplicationJanuary 14. 1943, serial No. 472,424

(ci. 23o-209) 3 Claims.

This invention relates to superchargers for internal combustion enginesand is particularly concerned with the provision of cooling means forthe output of the supercharger.

The supercharger impeller not only increases the pressure of the air orcombustible mixture delivered by the impeller, but it also causes aconsiderableV increase in the temperature of this air or combustiblemixture. This increase in temperature decreases the power available fromthe engine. Accordingly, it is desirable to provide means for reducingthe output temperature of the supercharger. It is an object of thisinvention to provide an elcient and compact supercharger cooling meanswhich utilizes the conventional diffuser vanes as part of the heatexchange sux'- face.

It is conventional practice t provide diffuser vanes at the output ofthe supercharger to slow l down the output velocity/of the air orcombustible mixture delivered by the supercharger. Accordingly, it is anobject of this invention to provide liquid cooling jackets about thediiiuser housing whereby these diffuser venes provide eiiicient heat Iexchange surfaces for cooling the outputof the' supercharger.

Further objects of the invention will become apparent in reading theannexed detailed description in connection with the drawing, in which:

Fig. 1 is an axial section through 'the supercharger impeller anddiiluser housing; and4 Fig. 2 is a partial sectional view of the diiusevanos to a reduced scale.

Referring to the drawing, a conventional centrifugal type superchargerimpeller, indicated at i6, is 'drivably connected to the impeller shaftl2. The supercharger is provided with arear usual in such superchargers,a plurality of diffuser g varies are provided in the diffuser chamberfor reducing the radially outward velocity of the air or combustiblemixture delivered by the supercharger. From this diffuser chamber theair or combustible mixture is distributed to the intake manifolds forthe various cylinders of the engine.

In accordance with the present invention. these diiuser vanes areclosely spaced about the impeller blades and comprise varies/28 and 30which are cast integral with the front and rear walls of the diiuserchamber 24.. Each of these venes extends approximately half way acrossthe chamber 24 and an annular disc-like plate 32 is disposed between theopposed vanes 28 and 30 to insure good heat conductivity therebetween. Aflangev 3l formed at the outer ends of either or both of the sets ofvanes 28 and 30 serves to retain the plate 32 in position. These vanes28 and 30 are inclined substantially tangential to the circumferentialpath of the up 2e of the impeller. blades whereby these varies act toreduce the output velocity of the air or combustible mixture deliveredIby the supercharger.

The front and rear walls of the diffuser chamber 24 are hollow toprovide annular jackets 38 and 38 through which water or other coolingfluid may be circulated, as schematically illustrated in Fig. 1. Wateror other cooling uid is circulated through the jackets 38 and 38 andthrough acooling radiator B0 by means of a pump I2. Accordingly, thediffuser vanes 28 and 30 also act as cooling fins for the superchargeroutput. This construction provides a metallic connection from each vaneto the walls of both water Jackets thereby providing a good heatconducting path from each of the vanes 2B or 3U to each of the jackets36 and 38. The provision of theannular disc-like plate 32 between thevanes 28 and 30 makes it unnecessary to exactly align these varies inorder to provide a metallic heat conducting path between the jacketsthrough the vanes. As illustrated, the liquid cooling jackets 36 and 38are connected in series although obviously these jackets could beconnected in parallel, if desired.

In operation, the supercharger impeller not only increases the pressureoi the air or combustible mixture delivered by the supercharger, but italso increases the temperature of this air or combustible mixture. Thisincrease in temperature of the air or combustible mixture decreases thepower available from the engine. Accordingly, the provision of anafter-cooler for reducing the temperature oi the supercharger output isobviously desirable. However, from the above description it is seen thatthe cooling means herein described is quite compact and efiicient and infact, the conventional super-charger has been mcdied merely by placing aliquid cooling Jacket around a diiluser chamber and the diffuser veneshave been. placed close together and modld to secure good heat transfer.Accordingly, except for an increase in the number of diiiuaer vanes, thecooling means herein`described does.

' the air or combustible mixture delivered by the supercharger, but inaddition these vanes actr as cooling fins for cooling this air orcombustible mixture. In fact, the exceptionally high velocity of the airor combustible mixture striking the diffuser vanesgreatly increases theamount of heat transferred as compared to that normally,

obtained with air cooling. l I

In addition to the above describedfunctions of the venes 28 and 30,these vanas may also act as a flame quencher in case of backiires. Inorder to quench backfire flames fairly long and thin passages havinggood heat transfer are required. Thus. the closely spaced cooling uns-Qiand 3l are ideally constructed as a 'flame qii'encher in case ofbackres. feature since the explosive pressure of a backfire may damageengine partss In addition, backilres present a dangerous-fire hazardbecause of accumulated fuel in the induction system. Thus, as a resultof a backfire, the accumulated fuel in the induction system may burnafter the engine has stopped and because of the closed-in air passages,such a ilre may not be observed.

From the above description it is seen that the vanes u and 30 have threefunctions, namely, (1) to reduce the output velocity of the air orcombustible mixture delivered by the supercharger impeller, (2) to coolthe air or combustible mixture delivered by the supercharger, and (3) toact as a flame quencher in case of backflres in the induction system.This is all accomplished simply by closely spacing the diffuser vanesand by providing a liquid cooled jacket for the diffuser chamber andheat exchange relation with these vanes.

While I have described my invention in detail inits present preferredembodiment, it will be obvious to those skilled in the art,afterunderstanding my invention, that various changes and modificationsmay be made therein without departing from the spirit or scope thereof.I aim in the appended claims to cover all such modifications andchanges.

I claim as my invention:

1. In a fluid compressor, an annular diffuser chamber receiving thecompressor output and having axially-spaced walls, eachof said spacedwalls comprising one wall of a liquid coolant jacket, a first set ofdiiIuser vanes integral with and extending inwardly into said annularchamber from one of said opposed axially-spaced walls. a second set ofdiffuser vanes integral with and extending inwardly into said annularchamber from the other of said opposed axially spaced walls, and anannular member disposed between the inner edges of said two sets ofdiffuser vanes, at least one of said sets of diffuser vanes havingflange means for supporting said annular member.

This is quite an important 2. In a fluid compressor, an annular diffuserchamber receiving the compressor output and having axially-spaced walls,each of said spaced walls comprising one wall .of a liquid coolant`iacket, a first set of diffuser vanes integral with and extendinginwardly into said annular chamber from one of said opposedaxially-spaced walls, a second set of diffuser vanes integral with andextending inwardly into said annular chamber from the other of saidopposed axially-spaced walls in substantial alinement with said firstset of varies, the inner edges of said two sets of vanes terminating inspaced relation to each other, and a substantially-flat annular memberdispod between the inner edges of said two sets of diffuser vanes andagainst which said vanes abut, at least one of said sets of diffuservanes having flange means for supporting said annular member.

3. In a fluid compressor, an annular diuser chamber receiving thecompressor output and having axially-spaced walls, each of said sDCedwalls comprising one wall of a liquid coolant jacket, a first set ofdiffuser vanes integral with and extending inwardly into said annularchamber from one of said axially-spaced walls, s. second set of diffuservanes extending integral with and extending inwardly into said annularchamber from the others of said axially-spaced walls. and asubstantially-flat annular member disposed between the inner edges ofsaid two sets of diffuser vanes, substantially the entire length of theinner edges of said diffuser vanes abutting against said annular memberand at least one of said sets of diffuser vanes having flange means forsupporting said annular member co-axial with said chamber.

HENRY C. HILL.

